An otolith (οτο-, oto-, ear + λιθος, lithos, a stone), also called statoconium or otoconium, is a structure in the saccule or utricle of the inner ear, specifically in the vestibular labyrinth of vertebrates. They have been identified in both extinct and extant vertebrates. The saccule and utricle, in turn, together make the otolith organs. They are sensitive to gravity and linear acceleration.